Question 147103
The key to this one is that the
3 angles of a triangle add up to {{{180}}} degrees
Call the angles {{{a}}},{{{b}}}, and {{{c}}}
{{{a = b + 20}}}
{{{c = 2b}}}
{{{a + b + c = 180}}}
Now substitute for {{{a}}} and {{{c}}} in the last equation
{{{b + 20 + b + 2b = 180}}}
{{{4b = 180 - 20}}}
{{{4b = 160}}}
{{{b = 40}}}
{{{a = b + 20}}}
{{{a = 40 + 20}}}
{{{a = 60}}}
{{{c = 2b}}}
{{{c = 80}}}
The angles are {{{60}}}, {{{40}}}, and {{{80}}} degrees
If you plug these numbers back into the original
equations, do they check OK? Try it.